将计就计

将计就计

Literally means:

turn one's trick against him

Actually means:

beat someone at his own game

It means deliberately collaborating with someone on his scheme and then turn his trick against at the right moment. It is usually used in cases when one sees through someone's scheme, he pretends to get entrapped and then beats the other in the right time by taking advantage of the other's ignorance, thus turning his position from passive into proactive.

迎合对方的计策，采用适当的计谋回击对方。通常的情况是，识破对方的计谋以后假装中计，再在对方不知不觉之中，采用合适的方式予以反击，从而变被动为主动。